Flashlight lamp and igniter mounting method



July 16, 1957 H. P. KEUKENS ETAL 2,799, 5

FLASHLIGHT LAMP AND IGNITER MOUNTING METHOD Filed April 10. 1953 IN VEN TORS HUBERTUS PIETER KEUKENS REINDER WESTRA AGENT United States, Parent D FLASHLIGHT LAMP AND IGNITER MOUNTING METHOD Hubertus Pieter Keukens and Reinder Westra, Eindhoven, Netherlands, assignors, by mesne assignments, to North American Philips Company, Inc., New York, N. Y., a corporation of Delaware Application April 10, 1953, Serial No. 347,978

' Claims priority, application Netherlands May 20, 1952 3 Claims. (Cl. 67-31) The invention relates to'a method of manufacturing flashlight lamps of the kind comprising a socket and a bulb provided with actinically burning material in the shape of foils, wires or strips, with a gas filler and with an electrical ignition device comprising a filament wire mounted on two stay wires and to flashlight lamps manufactured by this method.

The manufacture of these lamps, which is identical with the manufacture of incandescent lamps, comprises a manipulation for mounting the ignition device in the bulb provided with actinically burning material; this mounting must be carried out in a manner such that thereupon the gas filler can be introduced. For this purpose the ignition device is frequently mounted in a glass body, which is sealed in the neck of the bulb in a manner such that the bulb is closed but for a tube secured in this glass body and referred to hereinafter as an exhaust tube. In the manufacture of incandescent lamps a further, cheaper method is known, in which the filament wire and the stay wires are joined to form a unit by a non-conductive mass shaped in the form of a pearl or bead, referred to hereinafter as a bead mount, which is suspended in the bulb, the neck opening of which is turned upwards, the bead mount bearing on the ends of the stay wires, which are notconnected by the filament wire and which are bent for this purpose in a manner such that these ends point into opposite directions. Then the exhaust tube, through which the gas filler must be introduced into the bulb, is secured in the opening of the neck, the stay wires being fixed at the same time in the positions they have occupied, in a manner such that the filament wire takes up the desired position in the bulb and the stay wires project from the wall at the area where the exhaust tube is secured to the neck of the bulb.

It has been suggested to manufacture also flashlight lamps by this method (French patent specification No. 880,035). It has been found, however, that the industrial manufacture of such flashlight lamps give rise to difficulties due to the actinically burning material provided in the bulb. As a consequence, the bead mount suspended in the bulb, the neck opening of which is turned upwards, does not take up the position in which it can be secured by securing the exhaust tube in the bulb neck. By exerting a pressure the bead mount may, it is true, be moved into the desired position, but the member by means of which the pressure is exerted hinders the operation of securing the exhaust tube in the bulb neck and if the pressure member is released, the bead mount moves resiliently back. Therefore, according to the invention, the bead mount is arranged in the desired position in the bulb by means of a pressure member, then the ends of'the stay wires projecting from the bulb neck are bent along the outer surface of the bulb and secured there in position, after which the pressure member is removed and the exhaust tube is secured in the neck opening in a manner such that at the joint the stay wires extend through the wall.

2,799,152 Patented July 16, 1957 The invention relates to a method of providing an ignition device in the form of a bead mount in the bulb of a flashlight lamp and is characterised in that the bead mount is introduced into the bulb by means of a pressure member, the parts of the stay wires projecting from the bulb being bent along the outer surface of the bulb and secured there in position, the pressure member being re moved and the exhaust tube being secured in the neck in a manner such that the stay wires extend through the bulb wall at the joint.

For completeness sake it should be noted that certain types of flashlight lamps permit of suspending the bead mount in the bulb prior to the provision of actinically burning material. Even'in this case the aforesaid method is required in order to prevent the freely hanging bead mount from being pushed into an oblique position during the introduction of the actinically burning material; the result would be that the bead mount would be secured in this oblique position, which affects the light-time characteristic curve of the flashlight lamp.

The wires may be secured to the outer surface of the bulb by locally weakening the glass and pressing the wire ends against this weakened area. As an alternative, use may be made of an adhesive for this purpose. If desired, this operation may be combined with the application of the outer lacquer layer, the lacquer layer thus serving at the same time as an adhesive, or else, the lacquer layer already provided may be weakened locally. In a preferred embodiment of the invention the ends of the wires are clamped against the bulb wall. For this purpose use is made of, for example, a bulb having a substantially cylindrical neck, a ring fitting narrowly around the neck being slipped on the neck and the wire ends applied thereto.

The ends of the stay wires need be fastened only temporarily to the outer surface of the bulb. After the exhaust tube has been secured in the bulb neck, the ends of the stay wires may be released and connected in a suitable manner to the contact points of a cap secured to the bulb. In accordance with the invention it has been found that the wire ends secured to the outer sur face of the bulb, more particularly, to the substantially cylindrical neck portion of the bulb are very suitable to serve as current conductors. After the exhaust tube has been secured in the bulb neck, the gas filler introduced into the bulb and the exhaust tube sealed off, a flashlight lamp of simple and cheap construction is obtained, the socket of which is formed by the sealed-off exhaust tube and the neck of the bulb with the parts of the stay wires of the bead mount serving as current conductors, applied thereto. If desired, the bulb neck is not made circular, so that the flashlight lamp can be secured in a suitable holder only in one or in two positions in which the current conductors are in contact with current-supply contacts in the holder.

The method described above is particularly suitable for the manufacture of small flashlight lamps. However, if in these flashlight lamps use is made of ignition paste applied to the bead mount and if the exhaust tube is secured to the edge of the bulb neck by weakening the glass at this area, the ignition paste frequently ignites due to the heating of the stay wires bent around the weakened edge of the neck.

It has been found that this difficulty may be reduced by providing a not excessively small portion of the bead mount inside the bulb, i. e. the distance measured along the wire from the ignition paste to the seal is chosen to be more than 15 ms. For small types of bulbs, for example, bulbs having a capacity of less than 12 ccms. use is made of a bulb shape which deviates from the spherical types of this size produced in the manufacture of incandescent lamps, since the ignition must take place as much as possible in the centre. Therefore for flashlight lamps having a capacity of less than 12 ccms. use is made of an elongated shape, having an axis of at least 30 mms, this axis coinciding with the axis of the socket.

In order that the invention may be readily carried into effect, it will now be described in detail with reference to the accompanying drawing.

Figs. 1 to 3 illustrate the various steps of mounting an ignition device in the bulb of a flashlight lamp in accordance with the present invention,

Fig. 4 is a bottom plan view of the aforesaid flashlight lamp.

Fig. 1 illustrates the condition in which the glass bulb 1 which is provided with actinically burning, Wire-shaped material 2 and the capacity of which is about 8 ccms, the longitudinal axis having a length of 38 mms., the short axis a length of 22 rnrns, is arranged with the neck opening turned upwards, the bead mount 4 being then introduced into this neck opening; the actinically burning wire filler 2 hinders the bead mount in taking up the desired position, which is indicated by broken lines in the figure.

Pig. 2 shows the condition in which, after the bead mount has been introduced into the bulb by a pressure member (not shown), the ends of the stay wires 5 and 5' are bent along the outer surrace of the bulb wall and clamped against the neck 6 by means of a cardboard ring 7, so that the filament wire 8 takes up the desired position in the buib and the bead mount 4 is fixed in this position. The rotating gas flames 9 and 9 weaken the glass at the neck opening 3 of the bulb 11 and also the glass at the edge of the exhaust tube 10, which is held slightly spaced apart from the neck opening 3 and fterwards pressed against this neck.

Fig. 3 shows a flashlight lamp which is obtained after the exhaust tube 10, as described above, has been secured in the neck opening 3 and the bulb 1 has been provided with the desired gas filler, after which the exhaust tube has been sealed oil at 11. The socket of this flashlight lamp is constituted by the sealed-oil exhaust tube 10 and the neck of the bulb 6; to the outer surface of this neck are applied the two ends and 5 of the stay wires, forming part of the bead mount, operating as conductors for the current from supply contacts of a suitable holder (not shown).

Fig. 4 is a bottom view of a flashlight lamp as shown in Fig. 3. At 12 and 12 the cylindrical bulb neck 6 is provided with two ribs, so that the sectional area of the neck is not circular and the socket can thus be fixed in r a suitable holder only in the position in which current can be conveyed.

What is claimed is:

1. A method of mounting an ignition device having a head mount, a filament, and a plurality of stay wires in a flashlamp bulb having a neck portion comprising applying a coating of lacquer on the outer surfaces of said neck portion, inserting said ignition device through said neck portion and into said bulb with the ends of the stay wires projecting from the neck portion, bending the end portions of the stay wires so that they contact the outer surface of the neck portion, applying a close-fitting ring to said neck portion to hold said end portions in contact with the lacquered surface, fusing an exhaust tube to the end of said neck portion while causing said lacquer layer to soften locally and attach said ring to the said neck portion.

2. A flash lamp comprising an elongated bulb provided with a neck portion, an ignition device in said bulb including a bead mount, ignition paste applied to said head mount, a filament and a plurality of stay wires on said bead mount, said stay wires positioned around said neck portion and means fixing said stay wires to the outer surface of said neck portion including a substan tiaily flat ring and a lacquer coating on said neck portion, said stay wires operating as current conductors, and a sealed-off exhaust tube which together with said neck portion form a non-circular flash lamp mounting base, the distance of each of the stay wires from said ignition paste to the portion of said wire around said neck portion exceeds 15 mms. and the long axis of said bulb is at least mms, said flat ring additionally serving as a stop member.

3. A flash lamp comprising an elongated bulb provided with a neck portion, an ignition device in said bulb including a bead mount, ignition paste applied to said head mount, a filament and a plurality of stay wires on said bead mount, said stay wires positioned around said neck portion, and means fixing said stay wires to the outer surface of said neck portion including a substantially flat ring and a lacquer coating on said neck portion, said stay wires operating as current conductors, and a sealed-off exhaust tube which together with said neck portion form a non-circular flash lamp mounting base, said flat ring additionally serving as a stop member.

References Cited in the file of this patent UNITED STATES PATENTS 1,716,167 Grogan June 4, 1929 1,742,153 Stiles Dec. 31, 1929 2,006,568 Gustin July 2, 1935 2,023,628 Van Sant Dec. 10, 1935 2,359,483 Kuebler Oct. 3, 1944 2,699,659 Haas Jan. 18, 1955 

